1. Technical Field
The present invention relates to a method and system for alerting the driver (or other responsible party) to a situation where a child or other occupant may have been inadvertently left in a parked vehicle.
2. Background Art
It is possible for an inattentive or distracted vehicle driver to unintentionally leave an infant, young child, or other person in a parked vehicle. To prevent such an occurrence, it is therefore desirable to detect human occupancy in some or all of the vehicle seating positions, particularly in the rear seating row(s), and to provide an alert, reminder, and/or warning if the circumstances indicate that the driver has inadvertently left an occupant behind in the parked vehicle.
Systems have been proposed to address this concern; however none have provided an optimum solution. A detection and alerting system should ideally not be prone to false detections since this will result in a high number of false warnings to the driver which may, over time, cause the driver to disregard the warning altogether. Weight-based occupant detection systems have failed this test, since they cannot discern between a human occupant and any type of cargo sitting on the weight sensor.
Vision systems have also been proposed to detect human occupants. Although the cost and size of CMOS cameras has significantly improved in recent years, the processing power required to interpret the video and accurately detect human occupants is significant. The identification of live occupants using video is non-trivial, and covering multiple seating positions with a camera while detecting the infinite visual scenarios and lighting conditions presented by children in the rear seat (i.e. lying down on the seat, covered by a blanket, etc.) has proved to be an elusive task. It is also challenging for a video system to discern between an empty child seat left in the vehicle and a child seat that contains a small infant. Various template matching methodologies have been proposed but have not been successful due to the above reasons.
Accelerometers capable of detecting low-level vibrations have been proposed to identify occupant movement and heart rate, but they must be mounted to the vehicle floor pan or other structural member(s). Such sensors may be adequate for intruder detection, but for seat occupant detection they may be too far removed from the occupants to sense smaller occupants and assign them to unique seating positions. Essentially, the signal-to-noise ratio obtained from accelerometers for smaller occupants does not facilitate robust identification.
It has been proposed to position high-sensitivity sensors of various types in or on a vehicle component that is contacted by the driver to detect movement and/or heart rate in order to monitor the health and/or alertness of a driver. See, for example, U.S. Pat. No. 7,482,938.